connectionmanager.cpp

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/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#define FORBIDDEN_SYMBOL_ALLOW_ALL

#include <curl/curl.h>
#include "backends/networking/curl/connectionmanager.h"
#include "backends/networking/curl/networkreadstream.h"
#include "common/debug.h"
#include "common/fs.h"
#include "common/system.h"
#include "common/timer.h"

namespace Common {

DECLARE_SINGLETON(Networking::ConnectionManager);

}

namespace Networking {

ConnectionManager::ConnectionManager(): _multi(0), _timerStarted(false), _frame(0) {
    curl_global_init(CURL_GLOBAL_ALL);
    _multi = curl_multi_init();
}

ConnectionManager::~ConnectionManager() {
    stopTimer();

    //terminate all requests
    _handleMutex.lock();
    for (Common::Array<RequestWithCallback>::iterator i = _requests.begin(); i != _requests.end(); ++i) {
        Request *request = i->request;
        RequestCallback callback = i->onDeleteCallback;
        if (request)
            request->finish();
        delete request;
        if (callback)
            (*callback)(request);
    }
    _requests.clear();

    //cleanup
    curl_multi_cleanup(_multi);
    curl_global_cleanup();
    _multi = nullptr;
    _handleMutex.unlock();
}

void ConnectionManager::registerEasyHandle(CURL *easy) const {
    curl_multi_add_handle(_multi, easy);
}

Request *ConnectionManager::addRequest(Request *request, RequestCallback callback) {
    _addedRequestsMutex.lock();
    _addedRequests.push_back(RequestWithCallback(request, callback));
    if (!_timerStarted)
        startTimer();
    _addedRequestsMutex.unlock();
    return request;
}

Common::String ConnectionManager::urlEncode(Common::String s) const {
    if (!_multi)
        return "";
#if LIBCURL_VERSION_NUM >= 0x070F04
    char *output = curl_easy_escape(_multi, s.c_str(), s.size());
#else
    char *output = curl_escape(s.c_str(), s.size());
#endif
    if (output) {
        Common::String result = output;
        curl_free(output);
        return result;
    }
    return "";
}

uint32 ConnectionManager::getCloudRequestsPeriodInMicroseconds() {
    return TIMER_INTERVAL * CLOUD_PERIOD;
}

const char *ConnectionManager::getCaCertPath() {
#if defined(DATA_PATH)
    static enum {
        kNotInitialized,
        kFileNotFound,
        kFileExists
    } state = kNotInitialized;

    if (state == kNotInitialized) {
        Common::FSNode node(DATA_PATH"/cacert.pem");
        state = node.exists() ? kFileExists : kFileNotFound;
    }

    if (state == kFileExists) {
        return DATA_PATH"/cacert.pem";
    } else {
        return nullptr;
    }
#else
    return nullptr;
#endif
}

//private goes here:

void connectionsThread(void *ignored) {
    ConnMan.handle();
}

void ConnectionManager::startTimer(int interval) {
    Common::TimerManager *manager = g_system->getTimerManager();
    if (manager->installTimerProc(connectionsThread, interval, 0, "Networking::ConnectionManager's Timer")) {
        _timerStarted = true;
    } else {
        warning("Failed to install Networking::ConnectionManager's timer");
    }
}

void ConnectionManager::stopTimer() {
    debug(9, "timer stopped");
    Common::TimerManager *manager = g_system->getTimerManager();
    manager->removeTimerProc(connectionsThread);
    _timerStarted = false;
}

bool ConnectionManager::hasAddedRequests() {
    _addedRequestsMutex.lock();
    bool hasNewRequests = !_addedRequests.empty();
    _addedRequestsMutex.unlock();
    return hasNewRequests;
}

void ConnectionManager::handle() {
    //lock mutex here (in case another handle() would be called before this one ends)
    _handleMutex.lock();
    ++_frame;
    if (_frame % CLOUD_PERIOD == 0)
        interateRequests();
    if (_frame % CURL_PERIOD == 0)
        processTransfers();

    if (_requests.empty() && !hasAddedRequests())
        stopTimer();
    _handleMutex.unlock();
}

void ConnectionManager::interateRequests() {
    //add new requests
    _addedRequestsMutex.lock();
    for (Common::Array<RequestWithCallback>::iterator i = _addedRequests.begin(); i != _addedRequests.end(); ++i) {
        _requests.push_back(*i);
    }
    _addedRequests.clear();
    _addedRequestsMutex.unlock();

    //call handle() of all running requests (so they can do their work)
    if (_frame % DEBUG_PRINT_PERIOD == 0)
        debug(9, "handling %d request(s)", _requests.size());
    for (Common::Array<RequestWithCallback>::iterator i = _requests.begin(); i != _requests.end();) {
        Request *request = i->request;
        if (request) {
            if (request->state() == PROCESSING)
                request->handle();
            else if (request->state() == RETRY)
                request->handleRetry();
        }

        if (!request || request->state() == FINISHED) {
            delete (i->request);
            if (i->onDeleteCallback)
                (*i->onDeleteCallback)(i->request); //that's not a mistake (we're passing an address and that method knows there is no object anymore)
            _requests.erase(i);
            continue;
        }

        ++i;
    }
}

void ConnectionManager::processTransfers() {
    if (!_multi) return;

    //check libcurl's transfers and notify requests of messages from queue (transfer completion or failure)
    int transfersRunning;
    curl_multi_perform(_multi, &transfersRunning);

    int messagesInQueue;
    CURLMsg *curlMsg;
    while ((curlMsg = curl_multi_info_read(_multi, &messagesInQueue))) {
        if (curlMsg->msg == CURLMSG_DONE) {
            CURL *easyHandle = curlMsg->easy_handle;

            NetworkReadStream *stream = nullptr;
            curl_easy_getinfo(easyHandle, CURLINFO_PRIVATE, &stream);

            if (stream)
                stream->finished(curlMsg->data.result);

            curl_multi_remove_handle(_multi, easyHandle);
        } else {
            warning("Unknown libcurl message type %d", curlMsg->msg);
        }
    }
}

} // End of namespace Cloud